Universal serial bus (USB) memory cards or drives have become very popular and are well on their way to replacing floppy disk drives as the preferred storage devices for file transfers between personal computers. The USB architecture provides a fast bi-directional isochronous transfer of data between the external drive and the corresponding computer or host device. Moreover, USB flash drives provide greater read/write performance, significantly higher density data storage, and improved reliability as compared with conventional floppy drives.
One concern with the USB architecture, however, is how to leverage this technology in OEM telecommunications/data applications that require a greater degree of reliability with respect to mechanical, electrical, and environmental shock. For example, most commercially-available USB flash drives and their associated connector sets do not meet the requirements for such OEM applications. More specifically, the retention and lifecycle of standard USB connector sets are generally not acceptable for mission critical applications. OEM/ODM designers and manufacturers generally prefer memory devices having more mechanically robust form-factors (e.g., PC Card, Express Card, CompactFlash®, etc.). These devices use pin- and socket-type connector sets configured to ensure good module retention and longer insertion/removal cycle rates.
CompactFlash memory cards, for example, provide high-density storage, portability, low power consumption, and “plug and play” capability. CompactFlash cards, however, include a fifty pin connection and are only configured to fit within either a fifty pin CompactFlash socket or a sixty-eight pin PCMCIA socket. Furthermore, conventional CompactFlash cards that are fully compliant with the industry specifications do not have provisions for a serial bus interface. Express Cards are generally robust devices and include a metal housing and a standard serial communication protocol. Express Cards, however, are significantly larger than CompactFlash memory cards and are not considered an industry standard.